Characteristics of Soil Seed Banks in Different Eucalyptus urophylla×E.grandis Forest Types

To clarify the potential role of the soil seed bank in recovering species diversity and maintaining sustainable management of Eucalyptus plantation,field survey and laboratory observation experiment were conducted to study the character of soil seed banks in different Eucalyptus Forest types.The results were as follows:(1)the average seed storage of seed banks in 2-years-old new plantation and sprout forest of Eucalyptus urophylla×E.grandis was respectively 9 804 grain/m2 and 7 356 grain/m2,which was much higher than those in Castanopsis fissa mixed forest(3 614 grain/m2).It showed Eucalyptus plantation had abundant seed storage of seed banks.(2)Speices composition of the soil seed bank in new plantation were 15 species,belonging to 9 families;8 species were present in sprout forest of Eucalyptus,which were belonging to 7 families;16 species were present in Castanopsis fissa mixed forest,which were belonging to 9 families.The species composition of the soil seed bank in different plantation was mainly the herb and next to the shrub.(3)Seed bank vertical distribution pattern showed that the seeds mainly stored in dead branches of leaves and 0~5 cm of soil.The ecological dominance index of soil seed banks in different Eucalyptus forest was obviously higher than that in Castanopsis fissa mixed forest,but the Margalef richness index(R),Shannon-Wiener index(H'),Pielou evenness index(E),Simpson index(D)was lower than that in Castanopsis fissa mixed forest.The improving of species diversity in Eucalyptus should be to offer scientific management.